Food container with a tamper proof snap on closure



Dec. 1, 1970 A. w. KINNEY 3,544,338

FOOD CONTAINER WITH TAMPER PROOF SNAP ON CLOSURE Filed Jan. 8. 1968 INVENTOR.

A. W. KINNEY A 7' TORNE KS United States Patent 3,544,338 FOOD CONTAINER WITH A TAMPER PROOF SNAP ON CLOSURE Alfred W. Kinney, Kansas City, Mo., assignor to Phillips Petroleum Company, a corporation of Delaware Filed Jan. 8, 1968, Ser. No. 696,328 Int. Cl. B65b 61/12; B65d 17/00 US. Cl. 9171 8 Claims ABSTRACT OF THE DISCLOSURE A single service plastic container has a closure which is heat sealed to the neck of the container around a minor portion of the circumference of this neck.

BACKGROUND OF INVENTION The advent of the plastic container for milk and other consumable products has presented new problems in maintaining safe containers and protection of the customer. This is because the plastic container, being of a durable nature, may be used by the customer for storing toxic materials such as certain hydrocarbons and the like which are absorbed by the plastic container. These absorbed toxic materials are not removed by conventional cleaning methods and they migrate out of the bottle into any new consumable contents which might 'be packaged in the bottle.

The returnable, re-usable form of plastic milk bottle, while accepted on a limited basis after a very closely controlled field test, is not generally in favor with producers. Equipment has been designed to detect the presence of odors emanating from any hydrocarbons making up products that have been put in the bottle. It appears however that such equipment is not sensitive to all the myriads of other odors that might possibly attach themselves to the bottle. Promiscuous use of a plastic container for holding other products in the interim period between the consumption of the original contents as received from the dairy or other processing plant and its return to the processing plant cannot be controlled. Other problems that may occur in washing and sterilizing before re-use are conditions that further favor the use of single service containers for packaging of consumable products.

The single service container for milk and other consumable products is considered to be the most desirable. However, even the plastic containers designed for single service use have superior physical properties when compared to paper, and therein lies the temptation to wash and re-use these containers.

SUMMARY OF THE INVENTION It is an object of this invention to provide a single service plastic container with a closure that, once removed by the customer permits a re-closable container 3,544,338 Patented Dec. 1, 1970 for the customers purposes, yet is deformed such that it is impractical to re-cap it commercially. It is a further object of this invention to provide a method of securing a plastic closure to a single service plastic container so as to make commercial re-use of said container impractical. It is yet a further purpose of this invention to provide a quick and positive means to determine whether a bottle or a container has been re-used by a processor. It is yet a further object of this invention to provide a closure that will readily disclose by visible indication any attempts to tamper with the contents of the container.

In accordance with this invention a single service plastic container has a closure which is sealed to the neck of said container around the circumference of this neck for a distance within the range of to A of the circumference.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, forming a part herof, wherein like reference characters denote like parts in the various views, FIG. 1 is an axonometric view of a container in accordance with one embodiment of this invention with a closure aifixed thereto; FIG. 2 is an axonometric view of a container in accordance with one embodiment of this invention showing a lid that has been opened but not removed; FIG. 3 is an axonometric view of a container in accordance with one embodiment of this invention wherein the closure has been removed; and FIG. 4 is an axonometric view of an alternate embodiment of the invention wherein a film is sealed across the open mouth of the container.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The container can be made of any normally solid thermoplastic polymer suitable for blow molding such as vinyl polymers, polymers of at least one mono-1- olefin having 2 to 8 carbon atoms per molecule, acrylonitrile=butadiene-styrene resin,'acetal resins, phenoxy resins, polycarbonate resins, and the like. Particularly suitable polymers are those of at least one l-olefin se lected from the group consisting of ethylene, propylene and butene.

The closure may be of a material identical to that comprising the body of the container, however it can be made of any other material which can be sealed to the neck of the container. Generally the lid 'will be made of the material either identical to or similar to the material comprising the container. For instance if the coiltainer is made of polyethylene, then the lid will generally be made of polyethylene, polypropylene, or an ethylene butene copolymer.

The closure may be affixed to the container neck by any means which will result in leaving a portion of the closure on the bottle neck (or else tear a portion of the bottle neck 01f with the closure) as the lid is removed. The preferred means of afiixing the closure to the container is by heat sealing. Thus the seal must be stronger than at least one of the adjacent materials, that is, stronger than either the closure or the neck portion. Generally the weakest portion will be the part of the closure adjacent to the seal so that on removing the closure a portion of the closure remains afiixed to the lip of the container neck.

When a container is used by the customer, the closure may 'eitlierbe"taken "off completely or else the sealed area used as an integral hinge. If the lid is taken off completely the customer still has a reclosable container since the lid was sealed only along a minor portion of the circumference and thus can be re-afiixed over the open mouth of the container, even though the container is deformed so as to prevent re-use by a commercial processor.

If the customer,instead of tearing the lid completely oflt'of the body of the container, simply folds the lid back, using the sealed area on an integral hinge, stress lines will form radiating from said sealed area thus giving a visual indication that, the container closure has been} tampered with. This visual indication of opening of the lid is of particular importance since for some unexplainable reason shoppers will sometimes open containers of milk and other consumable products in the store'thus making them unfit for sale to another customer. By means 'of the use of the closure of the instant invention it can be determined 'by a quick visual observation of agroup of containers whether any of the closures have been tampered with. This, of course, also prevents re-use of the container using the same lid, since the stress lines will be visible after the initial opening of the container. In order to utilize this feature it is essential that the closure be made of a material which forms visible stress lines on being deformed. Particularly suitable materials in this regard are polyvinyl chloride, polymers of at least one mono-l-olefin selected from;the group consisting of ethylene, propylene, and butene wherein said polymer has a density (ASTM D 1505-.63T) of at least 0.940, and blends of polymers of at least one mono-l-olefin having 2 to 8 carbon atoms per molecule with polyisobutylene.

The closure is sealed around from about to about A of, the circumference of the neck, preferably about A; of the circumference of the neck. It may be either sealed continuously around this minor portion of the circumference or spot sealed within this minor area. But in any event, no seal is utilized around the major portion of the circumference. If a seal were utilized around the entire circumference, it would make the closure more difiicult to open, and would also deform the closure, not only sufficiently to prevent re-use, but also to the extent that .it would not be suitable for reclosing the container while being used by the customer. Furthermore by sealing the closure to the body of the container around only a minor portion of the circumference of the neck, a major portion of this circumference is available as a smooth pouring surface, whereas if the closure were sealed in spots around the entire circumference there would be not smooth pouring surface.

In a preferred embodiment the closure has a depend ing flange and the neck portion, adjacent the open mouth,

has an annular head or lip over which the closure snaps.

In most instances this provides a suflicient seal for the vent commercial application of another. closure.

Thecontainersof the instant invention can be filled with any consumable products, such as milk, prior to the aflixing of the closure to the open mouth of the container.

These containers are particularly suitable for packaging consumable liquid products.

They are preferably formed by blow molding. They can also be formed by vacuum forming or by thermoforming two flat sheets into the shape of a bottle as disannular bead 15 adjacent open mouth 16. Affixed over the open mouth 16 of body portion 12 is closure 18 having a grasping means in the form of .tab 20 which allows the customer to grasp the closure and open the container easily. This closure 18 is sealed to the neck portion 14 of the container along heat sealed line 22.

Referring now particularly to FIG. 3, there is shown the container of FIG. 1 with closure 18, removed; a portion 24 of closure 18 is shown remaining affixed to the neck portion of the container. While it is apparent that body portion 12 and closure 18 are sufficiently deformed to prevent commercial re-use, closure 18 can still be used by the consumer to cap the container while the contents are being used. The portion of depending flange 25 not torn ofi will fit around neck 14 to temporarily hold the closure on the body portion of the container.

Referring now to FIG. 2 there is shown the container of FIG. 1 wherein the closure 18 has been raised up to open the container but not torn off. Stress lines 26 formed as a result of deformation of the closure during opening are still visible after the closure has been pushed back down to temporarily cap the container as shown in this figure.

Referring to FIG. 4, there is shown a container in accordance to an alternate embodiment of this invention wherein web 28 is sealed across the open end of the body portion of the container, so as to provide a means to effect a hermetic seal. Closure 18 is sealed to neck portion 14 in the same manner as in the main embodiments.

Example A /2-gallon milk bottle similar to that shown in the figures was blow molded from 0.960 density (ASTM D 1505-63T) 0.6 melt index (ASTM D 1238-62T) ethylene homopolymer. The outer circumference at the head at the top of the neck area was approximately 4 inches. The wall thickness in this area was about 30 mils. A closure similar to that shown in the figures was thermoformed from 0.960 density (ASTM D 1505-63T) 0.2 melt index (ASTM D 1238-62T) ethylene homopolymer. The wall thickness of the depending flange of the closure was about 15 mils. This closure was snapped over the mouth of the bottle and heat sealed to the neck of the bottle at two points about Aa-inch Wide and spaced about it-inch apart. In removal of the closure a small portion of. said closure remained affixed to the bottle forming an uneven spot which precluded commercial re-use but which allowed replacement of the closure on a temporary basis.

While this invention has been described in detail for the purpose of illustration it is not to be construed as limited thereby but is intended to cover all changes and modifications within the spirit and scope thereof.

I claim:

1. A single service container filled with a consumable product comprising:

a body portion made of a normally solid thermoplastic material, said body portion having an open mouthed neck portion at the upper end thereof;-

a generally flat snap-on closure with a short depending flange, said closure being aflixed across said open mouth of said container, said closure being heat sealed to said neck portion around only from to A of the circumference of said neck portion in such a manner that said seal is stronger than at least one of the adjacent materials.

2. A container according to claim 1 where the thermoplastic material forming said body portion is selected from the group consisting of vinyl polymers, polymers of at least one mono-l-olefin having 2 to 8 carbon atoms per molecule, acrylonitrile-butadiene-styrene resins, a'cetal resins, phenoxy resins, and polycarbonate resins; said closure is fabricated of a normally solid thermoplastic material selected from the group consisting of vinyl polymers, polymers of at least one mono-l-olefin having 2 to 8 carbon atoms per molecule, acrylonitrile-butadienestyrene resins, acetal resins, phenoxy resins, polycarbonate resins and blends of polymers of at least one mono-1- olefin having 2 to 8 carbon atoms per molecule with polyisobutylene, and said closure is affixed to said neck by means of heat sealing.

3. A container according to claim 1 comprising in addition means to effect a hermetic seal of said product within said container.

4. A container according to claim 3 wherein said means to effect a hermetic seal comprises a film sealed across said open mouth.

5. A container according to claim 1 wherein said thermoplastic material comprising said body portion is a polymer of at least one mono-l-olefin selected from the group consisting of ethylene, propylene, and butene.

6. A container according to claim 5 wherein said consumable product is milk and wherein said closure is sealed around about A; of the circumference.

7. A container according to claim 6 wherein said closure is formed of a polymer of at least one mono-l-olefin selected from the group consisting of ethylene, propylene, and butene. a

8. A container according to claim 6 wherein said closure is formed of a polymer which forms visible stress lines on deformation.

References Cited UNITED STATES PATENTS FRANK W. LU'ITER, Primary Examiner R. HALPER, Assistant Examiner US. Cl. X.R. 

